He doesn’t do any special training for the event beyond exercising regularly. “I just go to the UIC gym,” he said. “I go three times a week and run on the treadmill, do stairs and the elliptical. I’ve been exercising for the last 14 years.”

During the event, waves of climbers begin their ascent every 15 minutes. The fastest climbers have the earliest time slots.

Grief, who is scheduled to begin climbing at 7 a.m., has set his goal to climb the 94 floors in less than 20 minutes. His best time so far has been 20 minutes.

“Spectators are always welcome,” said. “They go up to the Signature Room on the 95th floor and watch all the climbers from there.”